The skeletal remains found earlier this week in shallow desert graves outside Victorville, Calif., are believed to belong to a family that mysteriously disappeared in 2010, authorities said today.

San Bernardino County Sheriff John McMahon said at a news conference that forensic anthropologists were able to use dental records to positively identify Joseph McStay, 40, and his wife, Summer McStay, 43.

McMahon said authorities believe the skeletal remains two other bodies found at the gravesite are the couple's two young sons, however they are working to get official confirmation of their identities.

An off-road motorcyclist made the gruesome discovery on Monday when he noticed bones, which were apparently dragged out of the one-to-two-foot deep graves due to animal activity, McMahon said.

The sheriff said the bodies were otherwise intact and clothes were found in the graves, although he declined to elaborate about what items were found.

Relatives of the McStay family sobbed at the news conference. Michael McStay, Joseph's brother, said the past four years have been a "tough road" for relatives who have held out hope the family would be found safe.

"It's not really the outcome we were looking for," he said, "but it gives us courage to know they're together."

McMahon said the manner of death has been ruled homicide, however, he declined to comment on the possible cause of death or whether the family may have been targeted by a drug cartel.

The family of four hadn't been heard from since Feb. 4, 2010 and didn't indicate they had any plans to leave town, police said.

When detectives entered their home, they found rotten eggs on the counter and the family's two dogs in the backyard.

Police later found the family's vehicle abandoned near the United States-Mexico border, prompting authorities to wonder whether the family had crossed into Mexico.

Joseph's father, Patrick McStay, told ABCNews.com in 2010 that his son owned a company that designed interior decorative fountains and had done business in Tijuana as recent as a few months before his disappearance.

A video of a family matching the description of the McStays crossing into Mexico was obtained by police, however, McMahon said it was never confirmed to be the family and it was unclear whether the people seen in the video ever crossed back into the United States.